Image display projectors generate display images and project them on to display screens for viewing by one or more viewers. The display images are formed and projected by passing light from a high-intensity light source through an image-forming medium such as a translucent film or liquid crystal display. Alternatively, the display images are formed through use of digital light processing which uses digital micromirror devices to form the display images. It is generally known that the high-intensity light source implemented in known image display projectors typically generates relatively large amounts of heat. In addition, as the high-intensity light sources become capable of greater light intensities, e.g., 2000 or more lumens, the amount of heat generated by these light sources have also increased.
Conventional image display projectors include fans to blow air over the light sources and lamp reflectors to cool them by forced convection. In this regard, conventional image display projectors typically include vents to enable cool air to be drawn into the projectors as well as vents to enable heated air to be exhausted from the projectors. The fans employed in conventional image display projectors are typically incapable of supplying an adequate level of airflow to remove the ever-increasing heat levels produced by the high-intensity light sources because, for instance, of high flow resistance and associated pressure drops due to the relatively small sizes of the projectors. In one respect, the amount of space available in the conventional image display projectors typically precludes the use of fans having sufficient capacity to adequately cool the light sources and lamp reflectors. In another respect, the lamp reflectors are typically constructed to have insufficient surface area to enable adequate cooling by the conventional fans.
One solution is to employ small fans that require relatively small amounts of space and that may be operated to rotate at relatively high speeds to thus create the necessary airflow to sufficiently cool the light sources and lamp reflectors. However, high-speed fans often generate too much noise and may thus be disruptive during, for instance, presentations. In addition, high-speed fans are typically associated with relatively high expense and energy usage.